Speed-indicator.



J. K. STEWART.

SPEED INDICATOR.

APPLICATION FILED SEPT.21, 1911.

Patented Dec. 1, 1914.

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II: (4 n J. K. STEWART.

SPEED INDICATOR.

APPLICATION FILED SEPT. 21, 1911.

Patented Dec. 1, 1914.

2 SHEETSSHEET 2.

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ITED OFFICE.

JOHN K. STEWART, OF CHICAGO, ILLINOIS, ASSIGNOR TO STEWART-\VARNEESPEEDOMETER CORPORATION, OF VIRGINIA.

SPEED-INDICATOR.

Specification of Letters Patent.

Application filed September 21, 1911. Serial N 0. 650,565.

To all whom it ma concern:

Be it known t at I, JOHN Knbrnwan'r, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented new and useful Improvements in Speed -Indicators, of which thefollowing is a specification, reference being had to the accompanyingdrawings, forming a part thereof.

The purpose of this invention is to provide an improved form of speedmeasuring instrument by which the speed indicated may be read directlyin figures corresponding to the speed without any reference to agraduated scale such as is found in most instruments of this class.

The invention consists in certain features and elements of constructiondescribed and shown in the drawings as indicated in the claims.

In the drawings: Figure 1 is a front elevation of a speed indicatorembodying this invention, certain parts being broken away. F i 2 is aninterior elevation, certain portio s being broken away to reveal themechanism. Fig. 3 is a section taken as indicated at the line 3, 3, onFig. 2. Fig, 4 is a section taken as indicated at the line 4,4, on Fig.3. Fig. 5 is a staggered section taken as indicated atthe line 5,-5, onFig. 2. Fig. 6 is a detail face view of the speed indicating disks. Fig.7 is a detail of the toothed plate. 15. F ig. 8 is a detail view ofthenotched plate, 14. Fig. 9 is a detail elevation of the idler pinion, 18.

As may he understood from Fig. 1, the speed indicator which is thesubject of this invention is arranged within a case 'l,having a coverplate, 2, provided with a window. 2, at which it is arranged that thereshall appear numbers corresponding to the speed which is being measuredby the instrument. Sin e the instrument shown in the drawings isdesigned for use in connection with auto mobiles and where the speedis'desired to be known in terms of miles per hour, the numbersappearingat the window, 2, "v, ill correspond to the speed as measuredin thesatc-rins, and as usual there is iucorpm'atcd in the same case, 1.additional nwrhanism for registering the total number of miles lrav eledas well as the distancitraveled in a the bar, 4. The shaft, 3, isfurther provided PatentedDec. 1, 1914.

with a yoke, 6, rigid upon it and pivotally supporting,-in its laterallyextending arms, 6, a pair of weights, 7-7, having segmental gears, 7,out upon them in position to mesh with the racks, 4, of the bar, 4. Therotation of the shaft, 3, together with the yoke, 6, will cause theweights, 77, by reason of the centrifugal force thus generated, to

swing laterally outward and upward about their pivots, thus rotatingtheir gear segments, 7, and drawing the rack bar, 4, downward in theslotted end of the shaft, 3.

'Above the racks, 4, the bar, 4, is cylindrical and has formed upon it aseries of pe ripheral flanges, 4, equally spaced apart from one anotherso as to constitute a second rack and to mesh with a pinion, 8, mountedfast upon a shaft, 8", journaled in the casing. The upper end,4, of thebar, 4, is also cylindrical and is journaled in a bearing block, 4, inwhich it may both rotate and slide longitudinally. Thus it will be seenthat the rotation of the pinion, 8, which is caused by any up and downmovement of the rackbar, 4, due to variations of speed of the shaft, 3,and consequent movement of the weights, 77, may in, utilized to actuateany desired form of indicating mechanism.

Fig. 2 illustrates the gear train by which the indicating mechanism,(which is broken away to reveal the train) is connected for actuation bythe movement of the pinic l, 8. The shaft 8, has rigid with it a. gearwheel, 9, meshing with a pinion, 10, and with the latter there is rigida gear, 11, meshing with the pinion, 12, which carries the units disk.13, upon its hub, 12, as appears in Figs. 3 and 5. Also, rigid on thehub, 12, are two plates H and l5, having respectively upon theirperipheries a single notch, 14", and a pair of teeth, 15*, the latterpositioned so that the space between them registers with the notch, 14*,T he tens disks, 16, is carried by the hub, 17, of. a gear, 17, and anidler pinion, 18, by virtueof its special construction serves to connectthe units disk and the tens disk and cause a movement of the latteramounting to one step or subdivision thereof for each completerevolution of the ftu'mer. 'Figs. 5 and-9 indicate that every othertooth of the pinion, 13, is of half width only and that the toothedplate, 1.5, is positioned so that its teeth, 15, will mesh with thenarrow teeth as well as the wide teeth of the pinion, 18, while theplate, 14, is mounted so as to project into the spaces occasionedby theomission of half of every other toot-h of the pinion so, as to lock thepinion, 18, against rotation except when the notch, l'lv". registerswith one of the full width teeth of the pinion, which it doessimultaneously with the actuation of said pinion by the teeth, 15*, ofthe plate, 15. At such times the pinion, 18, being rotated by the amountof the two teeth, 15", will transmit this much movement to the gearwheel, 17, causing the disk, 16, to advance one division or ninneral,the gear, 17, being provided with two teeth for every division of thedisk, 16. During the remainder of the revolution of the units disk theplate, 14, serves to lock the tens disk against rotation'and thus topreserve proper positioning of its numeral before the window, 2.

With the mechanism thus far described, it will be seen that the movementof the speed indicating disks. 13'and 16, would be perfectly continuousand that any slight variation of speed would move the disk, 13, I

so that only when the speed happened to be an even number of miles perhour would the units figure stand in perfect re istration with theWindow, '2, and whenever a fraction of a mile was added to the speed,this figure would be moved out of registration with the window by anamount corresponding to the fractional increment of the speed.

Since this condition would often render it diflicult to read the numeralat all, and since it is deemed suflicient that the speed be known onlyto the nearest number of miles per hour, it is preferred to arrange thedisk, 13, so that it will move in steps of one subdivision or numeraland will stand at rest with the numeral in perfect registration with thewindow, 2, until the increment of speed amounts substantially to a wholemiliper hour. For this purpose the disk, 1 is provided with an auxiliaryill-armed star wheel, 19, of soft iron, back of which there is mountedfixedly in theease, l, a lllnglltt, so for which the arms of the starWheel, 19, are intended to serve, one at a time, as armatures. As eachnumeral of the disk, 13,

comes into position before the window, 2, the disk will be retained insuch position bv the attraction of the magnet, 20, for one (if the armsof the star wheel, 19, until the specdof the shaft, 3, is increasedsulliciently to overcome this attraction of the magnet, .20 and topermit the disk, 13, to ump ahead by one of its ten subdivisions. In thecase of decreasing speed, the tendency of the weights, 7-7. to return totheir normal and lowest position will operate in. the same way to returnthe disk, 13, toward its zero position in steps of one sub-divisioneach.

I claim 1. Tu a speedometer, in combination with a rotating member, adevil-o which responds to (change of speed of said member lrv-assuniinga different position f r each different speed: a magnet element and anarmature element. one of which is connected for rotation by said device,and the other of which is fixed. one .of said two elements beingmulti-polar and having its poles disposed in a ,circle about the axis ofrotation of said rotated element.

2-. In a speedometer. in combination with a rotating member, a. devicewhich responds to change of speed of rotation of said men-r her byassuming a different. position 1 or each different speed thereof; anunrnet element and an armature element. one of which is connected forrotation by said device and the other of which is fixed. the armatureele ment. having a series of soft iron projections disposed in a circleabout the axisof rotation of; said rotated element. the magnet havingone pole adjacent to the circle of such projections.

3. in a speedometer, in combination with a. rotating shaft and a deviceresponsive to speed operated by the rotation of the shaft; :1 train atuated by said speed-responsive device. a. part having a series of softiron projections -.lisp sed in a circle and mounted for rotation by saidtrain about an axis through the center ofsuch circle. and a magnethaving a pole disposed adjacent to the palh ot' rotation-of theprojections.

4. In a speedometer, comprising a case. a rotating shaft and a deviceresponsive to speed operated by the rotation of the shaft. the-vasebeing provided with a window. a rotatable element bearing a series ofnumerals all equi-(listant from the axis of rotation of said element andpositioned for display at the window of the case, a series of soft 'ironprojections rrespondin; respeel'ivelv to the aforwaid numerals, onnertedfor rotation with and disposed in a circle bout the axi of rotationthere of. a magnet lived in the case ha ing a pole adjacent to the pathof rotation of the pro: jortions. and a train connocling thnumerallw-irinq element with the speed responsi e device.

5. in a, speedometer, in combination with a rotating shaft. and a deviceresponsive to speed operated by the rotation of the shaft, a trainactuated by said speed-responsive device and ccmprising a units disk anda tens disk rotated by train shafts whose mo ements of rotation arerespectively as ten to one. an annular portion of each disk beingprovided with a series of numerals. the units shaft being parallel tothe tens shaft and the units disk overlapping the tens disk from oneside past the center but exposing the said annular portion thereof atone side.

t. In a speedometer, in combination with a rotating shaft and a de\iceresponsive to speed operated by the rotation ol. the shaft. a trainactuated by said speed-responsive device and comprising a units disk anda tens disk and'rotated by train shafts \vlnse movements ot rotation arerespectively as ten to one, an annular portion ol each dish beingprovided with a series of numerals, the units shaft being parallel tothe tens shaft and the units disk overlapping the tens disk from oneside past the center but exposing the said annular portion thereof atone side, and the tens disk having an incomplete annular siot toaccon'nnodate the shaft of the units disk.

7. In a speedometer. in combination with a rotating shaft and a deviceresponsive to speed operated by the rotation of the shaft: a trainconnected with the speed-responsive device; a units whee rotated by saidtrain: a. part rotating synchronously with said units wheel havingprojections spaced to correspond with the unit spaces of the unitswheel, and means presenting a yielding resistance to the movement ofsaid projections at one point in their path.

in a. speedometer, the combination of a. plurality oi rotatableindicating members positioned in cooperative relation to each other andprovided with numbers for affording a single reading at a given instantof time of the speed of a vehicle, means cooperating with each rotatablemember for retarding and arresting the rotation thereof, and actuatingmechanism for overcoming the resistance of said retarding and arrestingmeans and for imparting intermittent movci'ncnt to said indicatingmembers, said actuating mechanism operating to impart movement. to saidindicating members so that, the readings afforded by the indicatingmemtmrs will vary in accordance with an increase or decrease in thespeed of a vehicle.

9. in a speedometer. the combination of a plurality of rotatableindicating members positioned in coiiperative relation to each other androvidcd with numbers foiaffording a single reading at a given moment oftime of the speed of a vehicle. separate magnetic devices cooperatingwith said rotatable members for retarding and arresting the rotationthereof, and actuating means operating by yielding contact with one ofsaid r0- tatablc members for overcoming the resistance of said magneticdevices and im parting an intermittent rotation to said indicatingmembers, said actuating means opei ating to impart movement to saidindicating members so that thc readings atiorded by the indicatingmembers will vary in accordance with an increase or decrease in thespeed of a vehicle.

10. In a speedometer, the combination oi rotatable indicating memberspositioned in cooperative relation to each other, retarding meanscooperating with each member, actuating means tor directly opcrat-ingone r0- tatable l'nen'iber with an intermittent movement, means operatedby the intermittently actuated member for operating the other indicatingmember with alike movement, the tvvo said rotatable n'iemhers aliordinga single reading at a given moment of time of the speed of a vehicle.and actuating means operating to impart n'iovcment to said indieatingmembers so that the readings afforded by the indicating members willvary in accordance with an increase or decrease in the speed of avehicle.

11. in a speedometer, the combination of rotatable indicating.memberspositioned in cooperative relation to each other. each oi said membersbeing mounted tor free rotation, means for retarding the rotation ofsaid indicating members. a transmission shaft, a gear train. meansactuated by the gear train for inniarting movement to one of saidindicating members, and means for actuating the other indicating memberin unison with the first named member, said transmission shaft and geartrain operating to impart movement to the coiiperating indicatingmembers so that the reading atforded thereby will vary in accordancewith an increase or decrease in the speed of a vehicle.

12. In a speedometer, the combination of a movable indicating meansprovided with characters for denoting the speed of a ve hicle andarranged in sequential indicating positions. and means to move theindicating means to change the position of the latter with the speed ofthe vehicle comprising means to yieldingly force the indicating meansfrom one of its indicating positions to another. and means tending toretain the indicating means in a fixed position.

13. '[n a speedometer, the combination of a movable indicating meansprovided with characters for denoting the speed of a vehicle, andarranged in sequential indicating positions, means to move theindicating means to change the position of the latter with the speed ofthe vehicle comprising means to yieldingly force the indicating meansfrom one of its indicating positions my hand at Chicago, Illinois, this12th day to another, and a fixwl nmgnvt and {L body of September. 1911.of mu notic nmtvi'iui an) orted so as to be I 1 i movub io with thoindiciiting means and JOHN hr] IJWART' tending to retain the indicatingmeans in a Witnesses: fixed position. S'rAMiorE HUDSON,

In testimony h-"J'POf, I have hereunto set (7. B. SMiTH.

